for Journals by Title or ISSN
for Articles by Keywords
help

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2        [Sort by number of followers]   [Restore default list]

  Subjects -> VETERINARY SCIENCE (Total: 216 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 1)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 9)
Advances in Small Animal Medicine and Surgery     Hybrid Journal  
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 13)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 1)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 8)
American Journal of Primatology     Hybrid Journal   (Followers: 11)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 21)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 108)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 3)
Animal Nutrition     Open Access   (Followers: 8)
Animal Reproduction     Open Access   (Followers: 1)
Animal Reproduction Science     Hybrid Journal   (Followers: 4)
Animals     Open Access   (Followers: 7)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 6)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access  
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 3)
Australian Veterinary Journal     Hybrid Journal   (Followers: 15)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 5)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 2)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 10)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 8)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Buletin Veteriner Udayana     Open Access  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 9)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 4)
Equine Health     Full-text available via subscription   (Followers: 3)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 13)
Ethiopian Veterinary Journal     Open Access   (Followers: 5)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
FAVE Sección Ciencias Veterinarias     Open Access  
Folia Veterinaria     Open Access  
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal   (Followers: 1)
In Practice     Full-text available via subscription   (Followers: 2)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 4)
Indonesia Medicus Veterinus     Open Access  
Intas Polivet     Full-text available via subscription   (Followers: 1)
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 2)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 5)
İstanbul Üniversitesi Veteriner Fakültesi Dergisi     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 6)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 5)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 11)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Feline Medicine and Surgery Open Reports     Open Access  
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 11)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 29)
Journal of the Selva Andina Research Society     Open Access   (Followers: 1)
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 8)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 16)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 19)
Journal of Veterinary Medical Education     Partially Free   (Followers: 10)
Journal of Veterinary Medicine     Open Access   (Followers: 8)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 4)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 8)
Journal of Veterinary Research     Open Access  
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 4)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 2)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 6)
Jurnal Agripet     Open Access  
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 2)
Media Peternakan - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 2)
Medical Mycology Case Reports     Open Access  
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 11)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 3)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 1)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 3)
Open Access Animal Physiology     Open Access   (Followers: 4)
Open Journal of Animal Sciences     Open Access   (Followers: 4)
Open Journal of Veterinary Medicine     Open Access   (Followers: 4)
Pesquisa Veterinária Brasileira     Open Access  
pferde spiegel     Hybrid Journal  
Polish Journal of Veterinary Sciences     Open Access   (Followers: 3)
Pratique Médicale et Chirurgicale de l'Animal de Compagnie     Full-text available via subscription  
Preventive Veterinary Medicine     Hybrid Journal   (Followers: 10)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research & Reviews : Journal of Veterinary Science and Technology     Full-text available via subscription   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 10)
Research Journal of Veterinary Sciences     Open Access   (Followers: 9)
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access  
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Reprodução Animal     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
Revista Ciencia Animal     Open Access  
Revista Ciencias Veterinarias     Open Access  
Revista Científica     Open Access  
Revista Colombiana de Ciencias Pecuarias (Colombian journal of animal science and veterinary medicine)     Open Access   (Followers: 1)
Revista Complutense de Ciencias Veterinarias     Open Access  
Revista da Sociedade Brasileira de Ciência em Animais de Laboratório     Open Access  
Revista de Ciências Agroveterinárias     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Investigaciones Veterinarias del Perú     Open Access  
Revista de la Facultad de Medicina Veterinaria y de Zootecnia     Open Access   (Followers: 1)
Revista de Medicina Veterinaria     Open Access  
Revista de Salud Animal     Open Access  
Revista Mexicana de Ciencias Pecuarias     Open Access  
Revista MVZ Córdoba     Open Access  
Revista Veterinaria     Open Access  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
SA Stud Breeder / SA Stoetteler     Full-text available via subscription  
Schweizer Archiv für Tierheilkunde     Hybrid Journal  
Scientific Journal of Animal Science     Open Access   (Followers: 3)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 2)
Sokoto Journal of Veterinary Sciences     Open Access   (Followers: 1)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 1)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 3)
Theriogenology     Hybrid Journal   (Followers: 1)
Topics in Companion Animal Medicine     Hybrid Journal   (Followers: 3)
Transboundary and Emerging Diseases     Hybrid Journal   (Followers: 2)
Trends in Animal and Veterinary Sciences     Open Access   (Followers: 5)
Trends in Parasitology     Full-text available via subscription   (Followers: 7)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
Turkish Journal of Veterinary and Animal Sciences     Open Access  
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinária e Zootecnia     Open Access  
Veterinária em Foco     Open Access  
Veterinaria México     Open Access  
Veterinária Notícias     Open Access  
Veterinary Anaesthesia and Analgesia     Hybrid Journal   (Followers: 11)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 7)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 9)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 9)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 7)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 5)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 15)
Veterinary Dermatology     Hybrid Journal   (Followers: 7)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 9)
Veterinary Journal     Hybrid Journal   (Followers: 15)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 3)
Veterinary Medicine and Science     Open Access  
Veterinary Medicine International     Open Access   (Followers: 7)
Veterinary Medicine: Research and Reports     Open Access   (Followers: 4)
Veterinary Microbiology     Hybrid Journal   (Followers: 8)
Veterinary Nurse     Full-text available via subscription   (Followers: 4)
Veterinary Nursing Journal     Hybrid Journal   (Followers: 3)
Veterinary Ophthalmology     Hybrid Journal   (Followers: 6)
Veterinary Parasitology     Hybrid Journal   (Followers: 9)

        1 2        [Sort by number of followers]   [Restore default list]

Journal Cover Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2969 journals]
  • Streptococcus iniae cpsG alters capsular carbohydrate composition and is a
           cause of serotype switching in vaccinated fish
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Candice Heath, Christine M. Gillen, Panagiotis Chrysanthopoulos, Mark J. Walker, Andrew C. Barnes
      Streptococcus iniae causes septicaemia and meningitis in marine and freshwater fish wherever they are farmed in warm-temperate and tropical regions. Although serotype specific, vaccination with bacterins (killed bacterial cultures) is largely successful and vaccine failure occurs only occasionally through emergence of new capsular serotypes. Previously we showed that mutations in vaccine escapes are restricted to a limited repertoire of genes within the 20-gene capsular polysaccharide (cps) operon. cpsG, a putative UDP-galactose 4-epimerase, has three sequence types based on the insertion or deletion of the three amino acids leucine, serine and lysine in the substrate binding site of the protein. To elucidate the role of cpsG in capsular polysaccharide (CPS) biosynthesis and capsular composition, we first prepared isogenic knockout and complemented mutants of cpsG by allelic exchange mutagenesis. Deletion of cpsG resulted in changes to colony morphology and cell buoyant density, and also significantly decreased galactose content relative to glucose in the capsular polysaccharide as determined by GC–MS, consistent with epimerase activity of CpsG. There was also a metabolic penalty of cpsG knockout revealed by slower growth in complex media, and reduced proliferation in whole fish blood. Moreover, whilst antibodies raised in fish against the wild type cross-reacted in whole cell and cps ELISA, they did not cross-opsonise the mutant in a peripheral blood neutrophil opsonisation assay, consistent with reported vaccine escape. We have shown here that mutation in cpsG results in altered CPS composition and this in turn results in poor cross-opsonisation that explains some of the historic vaccination failure on fish farms in Australia.


      PubDate: 2016-08-27T15:20:53Z
       
  • Corrigendum to “Isoleucine 61 in PLO is important for the hemolytic
           activity of PLO of Trueperella pyogenes” [Vet. Microbiol. 182 (2016)
           196–201]
    • Abstract: Publication date: 15 November 2016
      Source:Veterinary Microbiology, Volume 195
      Author(s): Minghui Yan, Yunhao Hu, Jun Bao, Ya Xiao, Yue Zhang, Lingxiao Yang, Junwei Wang, Wenlong Zhang



      PubDate: 2016-08-27T15:20:53Z
       
  • Differentially expressed genes after viral haemorrhagic septicaemia virus
           infection in olive flounder (Paralichthys olivaceus)
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Jee Youn Hwang, Mun-Gyeong Kwon, Jung Soo Seo, Jung Wan Do, Myoung-Ae Park, Sung-Hee Jung, Sang Jung Ahn
      A strain of viral haemorrhagic septicaemia virus (VHSV) was isolated from cultured olive flounder (Paralichthys olivaceus) during epizootics in South Korean. This strain showed high mortality to olive flounder in in vivo challenge experiment. The complete genomic RNA sequences were determined and phylogenetic analysis of the amino acid sequences of glycoprotein revealed that this isolate was grouped into genotype IVa of genus Novirhabdovirus. Expression profile of genes in olive flounder was analyzed at day 1 and day3 after infection with this VHSV isolate by using cDNA microarray containing olive flounder 13K cDNA clones. Microarray analysis revealed 785 up-regulated genes and 641 down-regulated genes by at least two-fold in virus-infected fish compared to healthy control groups. Among 785 up-regulated genes, we identified seven immune response-associated genes, including the interferon (IFN)-induced 56-kDa protein (IFI56), suppressor of cytokine signaling 1 (SOCS1), interleukin 8 (IL-8), cluster of differentiation 83 (CD83), α-globin (HBA), VHSV-induced protein-6 (VHSV6), and cluster of differentiation antigen 9 (CD9). Our results confirm previous reports that even virulent strain of VHSV induces expression of genes involved in protective immunity against VHSV.


      PubDate: 2016-08-22T14:54:16Z
       
  • Evolution of African swine fever virus genes related to evasion of host
           immune response
    • Abstract: Publication date: Available online 20 August 2016
      Source:Veterinary Microbiology
      Author(s): Magdalena Frączyk, Grzegorz Woźniakowski, Andrzej Kowalczyk, Łukasz Bocian, Edyta Kozak, Krzysztof Niemczuk, Zygmunt Pejsak
      African swine fever (ASF) is a notifiable and one of the most complex and devastating infectious disease of pigs, wild boars and other representatives of Suidae family. African swine fever virus (ASFV) developed various molecular mechanisms to evade host immune response including alteration of interferon production by multigene family protein (MGF505-2R), inhibition of NF-κB and nuclear activating factor in T-cells by the A238L protein, or modulation of host defense by CD2v lectin-like protein encoded by EP402R and EP153R genes. The current situation concerning ASF in Poland seems to be stable in comparison to other eastern European countries but up-to-date in total 106 ASF cases in wild boar and 5 outbreaks in pigs were identified. The presented study aimed to reveal and summarize the genetic variability of genes related to inhibition or modulation of infected host response among 67 field ASF isolates collected from wild boar and pigs. The nucleotide sequences derived from the analysed A238L and EP153R regions showed 100% identity. However, minor but remarkable genetic diversity was found within EP402R and MGF505-2R genes suggesting slow molecular evolution of circulating ASFV isolates and the important role of this gene in modulation of interferon I production and hemadsorption phenomenon. The obtained nucleotide sequences of Polish ASFV isolates were closely related to Georgia 2007/1 and Odintsovo 02/14 isolates suggesting their common Caucasian origin. In the case of EP402R and partially in MGF505-2R gene the identified genetic variability was related to spatio-temporal occurrence of particular cases and outbreaks what may facilitate evolution tracing of ASFV isolates. This is the first report indicating identification of genetic variability within the genes related to evasion of host immune system which may be used to trace the direction of ASFV isolates molecular evolution.


      PubDate: 2016-08-22T14:54:16Z
       
  • DNA vaccine (P1-2A-3C-pCDNA) co-administered with Bovine IL-18 gives
           protective immune response against Foot and Mouth Disease in cattle
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Sivareddy Kotla, Bahire Sanghratna Vishanath, Dechamma H.J., Ganesh K., Suryanarayana V.V.S., G.R. Reddy
      Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals causing considerable economic loss in the affected countries. Presently used tissue culture inactivated vaccine protects the vaccinated animals for a short duration. DNA vaccines along with appropriate adjutants is one of the approach for the development of alternative vaccine. In the present study, we constructed P1-2A-3CpCDNA (containing P1-2A-3C coding sequences of FMDV Asia-1 Ind 63/72) and bovine IL-18 pCDNA plasmids and evaluated in cattle. Four groups of calves each group containing six calves were vaccinated with 200μg of plasmid DNA vaccine P1-2A-3CpCDNA, P1-2A-3CpCDNA+ bIL-18pCDNA and inactivated vaccine respectively where as fourth group was unvaccinated. P1-2A-3CpCDNA+bIL-18pCDNA vaccinated animals have shown higher levels of neutralizing antibodies and specific T-cell proliferation responses. Higher levels of CD4+ and CD8+ cells were observed in these animals. Similarly, IL-18 adjuvanted group has shown increased Th1 and Th2 cytokine responses. All the vaccinated animals were challenged with cattle adapted FMD homologous Asia1 virus two weeks after the booster dose. IL18 co administered DNA vaccine construct has protected four out of six animals challenged with homologous virus.


      PubDate: 2016-08-22T14:54:16Z
       
  • Chlamydia pecorum is the endemic intestinal species in cattle while C.
           gallinacea, C. psittaci and C. pneumoniae associate with sporadic systemic
           infection
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Jing Li, Weina Guo, Bernhard Kaltenboeck, Konrad Sachse, Yi Yang, Guangwu Lu, Jilei Zhang, Lu Luan, Jinfeng You, Ke Huang, Haixiang Qiu, Yaoyao Wang, Min Li, Zhangping Yang, Chengming Wang
      To investigate the prevalence and diversity of bovine Chlamydia spp. in cattle, whole blood from dairy and beef cattle in 11 provinces of China (n=2003) and vaginal swabs, whole blood samples, feces, milk samples from cows in a Yangzhou dairy farm (n=108) were examined using genus- and species-specific PCRs. In cattle from 11 provinces, 2.4% (48/2003) of whole-blood samples were positive for Chlamydia spp., and four Chlamydia species (C. pneumoniae, 41.7%, 20/48; C. psittaci, 22.9%, 11/48; C. gallinacea, 20.8%, 10/48; C. pecorum, 6.3%, 3/48) were identified. In a further study on a Yangzhou dairy farm, 64.8% (70/108) of the cows were positive for Chlamydia spp. C. pecorum was the intestinal endemic species (51/51, 100%), and C. gallinacea was the most frequent species in vaginal swabs (24/27, 88.9%), whole blood buffy coats (5/8, 62.5%) and milk (4/6, 66.7%). C. psittaci and C. pneumoniae were infrequently detected. DNA sequencing of the ompA gene demonstrated the presence of multiple in-herd C. pecorum serovars and single C. gallinacea and C. psittaci serovars which were identical with those of poultry from Yangzhou. This is the first report of C. gallinacea and C. pneumoniae in cattle. Further study is required to address the transmission of Chlamydia spp., in particular of C. gallinacea and C. pneumoniae from their natural hosts, and their potential pathogenic effect on health and production of cattle.


      PubDate: 2016-08-22T14:54:16Z
       
  • Surveillance, epidemiological, and virological detection of highly
           pathogenic H5N1 avian influenza viruses in duck and poultry from
           Bangladesh
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Wahedul Karim Ansari, Md. Shafiullah Parvej, Mohamed E. El Zowalaty, Sally Jackson, Stephen A. Bustin, Adel K. Ibrahim, Ahmed E. El Zowalaty, Md. Tanvir Rahman, Han Zhang, Mohammad Ferdousur Rahman Khan, Md. Mostakin Ahamed, Md. Fasiur Rahman, Marzia Rahman, K.H.M. Nazmul Hussain Nazir, Sultan Ahmed, Md. Liakot Hossen, Md. Abdul Kafi, Mat Yamage, Nitish C. Debnath, Graba Ahmed, Hossam Ashour, Md. Masudur Rahman, Ayman Norredin, Md. Bahanur Rahman
      Avian influenza viruses (AIVs) continue to pose a global threat. Waterfowl are the main reservoir and are responsible for the spillover of AIVs to other hosts. This study was conducted as part of routine surveillance activities in Bangladesh and it reports on the serological and molecular detection of H5N1 AIV subtype. A total of 2169 cloacal and 2191 oropharyngeal swabs as well as 1725 sera samples were collected from live birds including duck and chicken in different locations in Bangladesh between the years of 2013 and 2014. Samples were tested using virus isolation, serological tests and molecular methods of RT-PCR. Influenza A viruses were detected using reverse transcription PCR targeting the virus matrix (M) gene in 41/4360 (0.94%) samples including both cloacal and oropharyngeal swab samples, 31 of which were subtyped as H5N1 using subtype-specific primers. Twenty-one live H5N1 virus isolates were recovered from those 31 samples. Screening of 1,868 blood samples collected from the same birds using H5-specific ELISA identified 545/1603 (34%) positive samples. Disconcertingly, an analysis of 221 serum samples collected from vaccinated layer chicken in four districts revealed that only 18 samples (8.1%) were seropositive for anti H5 antibodies, compared to unvaccinated birds (n=105), where 8 samples (7.6%) were seropositive. Our result indicates that the vaccination program as currently implemented should be reviewed and updated. In addition, surveillance programs are crucial for monitoring the efficacy of the current poultry vaccinations programs, and to monitor the circulating AIV strains and emergence of AIV subtypes in Bangladesh.


      PubDate: 2016-08-22T14:54:16Z
       
  • Genotyping of Staphylococcus aureus in bovine mastitis and correlation to
           phenotypic characteristics
    • Abstract: Publication date: Available online 17 August 2016
      Source:Veterinary Microbiology
      Author(s): Karin Artursson, Robert Söderlund, Lihong Liu, Stefan Monecke, Jenny Schelin
      Reducing the prevalence of mastitis caused by Staphylococcus aureus (S. aureus) is essential to improve animal health and reduce economic losses for farmers. The clinical outcome of acute mastitis and risk of progression to persistent mastitis can, at least to some extent, be related to genetic variants of the strain causing the infection. In the present study we have used microarrays to investigate the presence of virulence genes in S. aureus isolates from dairy cows with acute clinical mastitis (n=70) and correlated the findings to other genotypic and phenotypic characteristics. Among the most commonly found virulence factors were genes encoding several hemolysin types, leukocidins D and lukM/lukF-P83, clumping factors A and B, fibrinogen binding protein and fibronectin-binding protein A. Some virulence factors e.g. fibronectin-binding protein B and Staphylococcus aureus surface protein G were less common. Genes coding for several staphylococcal enterotoxins and toxic shock syndrome toxin-1 (TSST-1) were commonly found, especially in one major pulsotype. No beta-lactamase genes were found in any common pulsotype, while present in some rare pulsotypes, indicated to be of human origin. Production of TSST-1, enterotoxins, hemolysins and beta-lactamase could all be positively correlated to presence of the corresponding genes. This study reveals a number of genotypic differences and similarities among common and rare pulsotypes of S. aureus from cases of mastitis in Sweden. The results could help the design of diagnostic tools to guide on-farm interventions according to the expected impact on udder health from a specific S. aureus genotype.


      PubDate: 2016-08-18T14:47:19Z
       
  • Unusual outbreak of post-weaning porcine diarrhea caused by single and
           mixed infections of rotavirus groups A, B, C, and H
    • Abstract: Publication date: Available online 17 August 2016
      Source:Veterinary Microbiology
      Author(s): Bruna Letícia Domingues Molinari, Flávia Possatti, Elis Lorenzetti, Alice Fernandes Alfieri, Amauri Alcindo Alfieri
      Rotaviruses (RVs) are a major cause of severe diarrhea in humans and animals. Five of the nine RV groups (RVA, RVB, RVC, RVE, and RVH) have been previously detected in pigs; however, in pig herds worldwide, most studies highlight diarrhea outbreaks caused by RVA. In the present study, we describe detection and characterization of RV groups A, B, C, and H in fecal samples from pigs with single and mixed infections during a post-weaning diarrhea outbreak. The outbreak occurred in a single pig herd routinely vaccinated with an inactivated commercial vaccine for neonatal diarrhea control that included the RVA OSU (G5P[7]) strain. RVC (78%) was the most prevalent group found in single (34%) and mixed (44%) infections, followed by RVA (46%), RVB (32%), and RVH (18%). Phylogenetic analysis of three RVA strains allowed the characterization of two distinct G/P genotypes represented by G5P[13] and G9P[23], different from G5P[7] found in vaccines. Regardless of the RV group, mixed infections (54%) were more prevalent than single infections. Detection of RVB or RVH was associated with the presence of other RV groups, suggesting a secondary action of these RV groups in the reported outbreak. The detection of RV groups B, C, and H in the same pig herd suggests that these RVs act as causative agents of diarrhea and should be included in the diagnostic tests of porcine enteric diseases. These data provide new epidemiological information on RV diversity that need to be addressed in future studies for a better understanding and prevention of RV infections.


      PubDate: 2016-08-18T14:47:19Z
       
  • The detection of fosfomycin resistance genes in Enterobacteriaceae from
           pets and their owners
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Hong Yao, Dongfang Wu, Lei Lei, Zhangqi Shen, Yang Wang, Kang Liao
      The aim of this study was to investigate the prevalence of fosfomycin resistance and molecular characteristic of fosfomycin-resistant strains isolated from companion animals and their owners. A total of 171 samples collected from pets and pet owners in a Chinese veterinary teaching hospital were screened for the presence of phenotype and genotype of fosfomycin-resistance by selective media containing fosfomycin and PCR & sequencing. Among 171 samples tested, nineteen isolates were resistant to fosfomycin. Sixteen and three of these fosfomycin-resistant isolates were positive for fosA3 and fosA genes, respectively. The fosA3 gene was detected both in chromosomes and plasmids in bacteria. All of the fosA3 gene-positive isolates except one were CTX-M producers and nearly half (7/16) of them also harbored the rmtB gene. The fosA3 gene-carrying plasmids, which were readily transferrable to recipient E. coli J53 by conjugation, conferred resistance to multiple antimicrobial agents. Genetic structures were IS26-385bp-fosA3-1810bp-IS26 (n=11) and IS26-385bp-fosA3-588bp-IS26 (n=5). Molecular typing indicated that two fosA3-positive isolates from dogs were genetically identical to the isolates from the pet owners. Our results indicated that active transmission of fosA3-mediated fosfomycin resistance has occurred among Enterobacteriaceae isolated from pets and their owners by both horizontal transfer and clonal expansion.


      PubDate: 2016-08-18T14:47:19Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192




      PubDate: 2016-08-18T14:47:19Z
       
  • Pathogenicity of virulent infectious bronchitis virus isolate YN on hen
           ovary and oviduct
    • Abstract: Publication date: Available online 17 August 2016
      Source:Veterinary Microbiology
      Author(s): Qi Zhong, Yan-xin Hu, Ji-hui Jin, Ye Zhao, Jing Zhao, Guo-zhong Zhang
      Avian infectious bronchitis is an economically important poultry disease caused by avian infectious bronchitis virus (IBV). IBV isolate YN is a virulent strain, which is genetically similar to most of the prevalent strains in China. In this study, 21-day-old commercial laying hens were infected with IBV strain YN. The damaging effects of the virus on the reproductive organs were evaluated with clinical observations, gross autopsy and histopathological examinations during the 100-day monitoring period post infection. IBV strain YN infection caused a death rate of 40.5%. Microscopic lesions were observed on the ovary post-infection, but were restricted to the acute infection period. The pathological damage to the cystic oviducts were observed throughout the surveillance period. This study provides detailed information on the pathological changes in the hen ovary and oviduct after challenge with IBV strain YN, which could provide a better understanding about the pathogenicity of IBV.


      PubDate: 2016-08-18T14:47:19Z
       
  • Chicken IL-7 as a potent adjuvant enhances IBDV VP2 DNA vaccine
           immunogenicity and protective efficacy
    • Abstract: Publication date: Available online 17 August 2016
      Source:Veterinary Microbiology
      Author(s): Shanshan Huo, Yuzhu Zuo, Nan Li, Xiujin Li, Yonghong Zhang, Liyue Wang, Hao Liu, Jianlou Zhang, Dan Cui, Pingyou He, Jian Xu, Yan Li, Xiutong Zhu, Fei Zhong
      Our previous work has demonstrated that the mammalian interleukin-7 (IL-7) gene can enhance the immunogenicity of DNA vaccine. Whether chicken IL-7 (chIL-7) possesses the ability to enhance the immunogenicity of VP2 DNA vaccine of infectious bursal disease virus (IBDV) remained unknown. To investigate this, we constructed a VP2 antigenic region (VP2366) gene and chIL-7 gene vectors, co-immunized chicken with these vectors and analyzed the effects of the chIL-7 gene on VP2366 gene immunogenicity. Results showed that co-administrated chIL-7 gene with VP2 DNA vaccine significantly increased specific serum antibody titers against IBDV, and enhanced lymphocyte proliferation and IFN-γ and IL-4 productions. More importantly, chIL-7 gene significantly increased VP2366 gene-induced protection against virulent IBDV infection, indicating that the chIL-7 gene possessed the capacity to enhance VP2366 DNA vaccine immunogenicity, and therefore might function as a novel adjuvant for IBDV VP2 DNA vaccine. Mechanically, chIL-7 could stimulate the common cytokine receptor γ chain (γc) expressions in vitro and in vivo, which might be involved in chIL-7 enhancement of the immunogenicity of VP2 DNA vaccine.


      PubDate: 2016-08-18T14:47:19Z
       
  • Two strains of Mycoplasma synoviae from chicken flocks on the same layer
           farm differ in their ability to produce eggshell apex abnormality
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): S. Catania, F. Gobbo, D. Bilato, L. Gagliazzo, M.L. Moronato, C. Terregino, J.M. Bradbury, A.S. Ramírez
      Mycoplasma synoviae (Ms) is considered to be an economically important poultry pathogen. Although the full economic costs of infection in layer chickens are still under debate, the prevalence of Ms is known to be high in some countries and earlier reports have shown a correlation between infection and Eggshell Apex Abnormality (EAA). This work is a continuation of an earlier study of a clinical case of EAA on a layer hen farm where the presence of two different strains of Ms, based on the sequence of the 5′ end of the vlhA gene, was demonstrated. Both strains could be detected in the trachea but only one (designated strain PASC8) appeared able to colonize the oviduct, while the other (designated TRACH) was not found in the oviduct and has not been related to EAA. The PASC8 partial vlhA gene sequence differs from that of the TRACH in having a 39 nucleotide deletion in the proline rich region and three point mutations in the RIII region. Based on this information an experimental infection was performed in SPF chickens using groups infected with either the PASC8 or the TRACH strain and a non-infected control group. Both Ms strains were detected in the trachea of infected birds, but only the PASC8 strain was found in the oviduct. Furthermore, EAA developed only in the group infected with PASC8 strain. Compared to the control group, both strains produced an adverse impact on egg production: a decrease in the numbers laid and in their average weight (P <0.05) This work demonstrates a difference in oviduct tropism between two Ms strains and a possible relationship to the production of EAA in experimental conditions.


      PubDate: 2016-08-18T14:47:19Z
       
  • Role of autophagy in cellular response to infection with Orf virus Jilin
           isolate
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Yungang Lan, Gaili Wang, Deguang Song, Wenqi He, Di Zhang, Houshuang Huang, Jingying Bi, Feng Gao, Kui Zhao
      Autophagy is a conserved catabolic process of the cell, which has been described to be involved in the development of various viral diseases. However, the role of autophagy in Orf virus (ORFV) replication remains unknown. In this study, we provide the first evidence that ORFV infection triggered autophagy in primary ovine fetal turbinate cells (OFTu) based on the appearance of abundant double- and single-membrane vesicles, the accumulation of LC3 fluorescent puncta, the enhancement of LC3-I/-II conversion, and autophagic flux. Moreover, modulation of ORFV-induced autophagy by rapamycin (RAPA), Earle's balanced salts solution (EBSS), chloroquine (CQ) or 3-methyladenime (3-MA) does not affect virus production. In conclusion, these results suggest that autophagy can be induced in host cells by ORFV infection, but which maybe not essential for ORFV replication.


      PubDate: 2016-08-13T14:42:32Z
       
  • Impact of porcine reproductive and respiratory syndrome virus and porcine
           circovirus-2 infection on the potency of the classical swine fever vaccine
           (LOM strain)
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Seong-In Lim, Hye-Young Jeoung, Byounghan Kim, Jae-young Song, Jaejo Kim, Ha-Young Kim, In-Soo Cho, Gye-Hyeong Woo, Joong-Bok Lee, Dong-Jun An
      The classical swine fever (CSF) vaccine, which is derived from the LOM strain of the CSF virus (CSFV), induces protective immunity against CSFV infection. However, several factors influence vaccine efficacy. Evidence suggests that infection by porcine reproductive and respiratory syndrome virus (PRRSV) and/or porcine circovirus 2 (PCV2) reduces the efficacy of several vaccines. Here, we examined the effect of PRRSV or PCV2 alone or co-infection by PRRSV/PCV2 on the potency of the LOM vaccine in pigs. Neither CSFV antibody levels nor the period during which CSFV antigens were detectable in LOM-vaccinated pigs were negatively affected by infection by PRRSV or PCV2. However, co-infection with PRRSV/PCV2 may affect the replication or activity of the CSF vaccine virus in pigs vaccinated with the LOM strain, although CSFV antibody levels were not negatively affected. Nevertheless, the LOM vaccine afforded complete protection against a virulent strain of CSFV.


      PubDate: 2016-08-13T14:42:32Z
       
  • Longitudinal characterization of monophasic Salmonella Typhimurium
           throughout the pig’s life cycle
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Laura Fernandes, Maria Madalena Centeno, Natacha Couto, Telmo Nunes, Virgílio Almeida, Lis Alban, Constança Pomba
      Swine have been described as an important reservoir of multidrug resistant monophasic Salmonella Typhimurium, though information on its ecology is scarce. A longitudinal study was performed in order to elucidate the Salmonella 4,[5],12:i:- dynamics throughout the pig’s production cycle. A total of 209 faecal samples were collected from 10 sows and in six sampling times during the life of 70 pigs from a Portuguese industrial farm, and 43 isolates of S. 4,[5],12:i:- were identified and characterized regarding clonality and antimicrobial resistance phenotype and genotype. Most isolates (n=42) exhibited resistance to at least ampicillin, kanamycin, neomycin, streptomycin, tetracycline and sulfonamides (encoded by bla TEM, aphAI-IAB, strA, strB, tetB and sul2, respectively). Isolates obtained during the finishing phase showed additional resistance to chloramphenicol and florfenicol (floR), gentamicin and netilmicin (aac(3′)-IV). To our knowledge, this study is the first description of aphAI-IAB in S. 4,[5],12:i:-. PFGE analysis showed uneven distribution of isolates into three clusters, A (n=34), B (n=8) and C (n=1). PFGE cluster A was predominant in sows (n=5) and piglets in the farrowing phase (n=17) and in pigs in the early finishing phase (n=11) suggesting a carryover from birth to adult age. The introduction of PFGE cluster B isolates in adulthood could have had an external source, reinforcing the relevance of environmental transmission in the farm ecosystem. This study reveals a dynamic interaction between monophasic S. Typhimurium and the pressures exerted under an intensive swine production setting.


      PubDate: 2016-08-09T20:28:41Z
       
  • First screening for Brachyspira hampsonii in Swiss pigs applying a new
           high resolution melting assay
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Simone Scherrer, Anna Borgström, Daniel Frei, Max M. Wittenbrink
      A new High Resolution Melting (HRM) assay was developed for the rapid detection of Brachyspira (B.) hampsonii. B. hampsonii occurs in different European countries, however, until today it has not been encountered in Switzerland. Four B. hampsonii reference strains were used to develop the HRM assay: B. hampsonii clade I ATCC BAA2463 and clade II ATCC BAA2464 strain, as well as two isolated strains P280/1 from the UK and the German isolate 5369-1x/12. A conserved region of the nox gene was used to design B. hampsonii-specific primers. The HRM melting curves for the four reference strains showed reproducible difference graphs with distinct differences between the four strains based on a slight variation between the four amplicon sequences. In addition, DNA from 22 B. hampsonii strains representing four genetic B. hampsonii groups was used to validate the method. Melting temperatures in the interval between 73.1 and 74°C were obtained for all B. hampsonii strains and allow differentiating B. hampsonii from other Brachyspira species. In total 897 Swiss porcine fecal Brachyspira isolates, cultured between 2009 and 2015, were analysed by the HRM protocol. B. hampsonii was not detected among these Swiss Brachyspira isolates. In conclusion, the rapid and low-cost HRM approach allows a sensitive and specific identification of B. hampsonii.


      PubDate: 2016-08-09T20:28:41Z
       
  • Virulence type and tissue tropism of Staphylococcus strains originating
           from Hungarian rabbit farms
    • Abstract: Publication date: 25 September 2016
      Source:Veterinary Microbiology, Volume 193
      Author(s): Zoltán Német, Ervin Albert, Krisztina Nagy, Edit Csuka, Ádám Dán, Ottó Szenci, Katleen Hermans, Gyula Balka, Imre Biksi
      Staphylococcosis has a major economic impact on rabbit farming worldwide. Previous studies described a highly virulent variant, which is disseminated across Europe. Such strains are reported to be capable of inducing uncontrollable outbreaks. The authors describe a survey conducted on 374 Staphylococcus strains isolated from rabbit farms, mostly from Hungary, between 2009 and 2014, from a variety of pathological processes. The virulence type of the strains was determined using a multiplex PCR system. 84.2% of the strains belonged to a previously rarely isolated atypical highly virulent type. Only 6.1% belonged to the typical highly virulent genotype. Even low virulent strains were present at a higher percentage (6.4%). For a small group of strains (3.2%) the detection of the femA gene failed, indicating that these strains probably do not belong to the Staphylococcus aureus species. The results reveal the possibility of the asymptomatic presence of highly virulent strains on rabbit farms. “Non-aureus” Staphylococcus sp. can also have a notable role in the etiology of rabbit staphylococcosis. An association with the lesions and the virulence type was demonstrated. Statistical analysis of data on organotropism showed a significant correlation between septicaemia and the highly virulent genotype.


      PubDate: 2016-08-09T20:28:41Z
       
  • Epidemiological survey of enteric viruses in wild boars in the Czech
           Republic: First evidence of close relationship between wild boar and human
           rotavirus A strains
    • Abstract: Publication date: Available online 4 August 2016
      Source:Veterinary Microbiology
      Author(s): Romana Moutelíková, Lucie Dufková, Jiří Kamler, Jakub Drimaj, Radim Plhal, Jana Prodělalová
      Population of wild boar is increasing in the whole Europe, the animals migrate close to human habitats which greatly increases the possibility of natural transmission between domestic animals or humans and wild boars. The aim of the study was to estimate in population of free-living wild boar in the Czech Republic the prevalence of enteric viral pathogens, namely rotavirus groups A and C (RVA and RVC), porcine reproductive and respiratory syndrome virus (PRRSV), and members of family Coronaviridae (transmissible gastroenteritis virus − TGEV, porcine epidemic diarrhea virus − PEDV, porcine respiratory coronavirus − PRCV, and porcine hemagglutination encephalomyelitis virus − PHEV) and Picornaviridae,(teschovirus A − PTV, sapelovirus A − PSV, and enterovirus G − EV-G). In our study, stool samples from 203 wild boars culled during hunting season 2014-2015 (from October to January) were examined by RT-PCR. RVA was detected in 2.5% of tested samples. Nucleotide analysis of VP7, VP4, and VP6 genes revealed that four RVA strains belong to G4P[25]I1, G4P[6]I5, G11P[13]I5, and G5P[13]I5 genotypes and phylogenetic analysis suggested close relation to porcine and human RVAs. The prevalence of RVC in wild boar population reached 12.8%, PTV was detected in 20.2%, PSV in 8.9%, and EV-G in 2.5% of samples. During our study no PRRSV or coronaviruses were detected. Our study provides the first evidence of RVC prevalence in wild boars and indicates that wild boars might contribute to the genetic variability of RVA and also serve as an important reservoir of other enteric viruses.


      PubDate: 2016-08-04T20:13:02Z
       
  • Simulating the epidemiological and economic effects of an African swine
           fever epidemic in industrialized swine populations
    • Abstract: Publication date: Available online 4 August 2016
      Source:Veterinary Microbiology
      Author(s): Tariq Halasa, Anette Bøtner, Sten Mortensen, Hanne Christensen, Nils Toft, Anette Boklund
      African swine fever (ASF) is a notifiable infectious disease with a considerable impact on animal health and is currently one of the most important emerging diseases of domestic pigs. ASF was introduced into Georgia in 2007 and subsequently spread to the Russian Federation and several Eastern European countries. Consequently, there is a non-negligible risk of ASF spread towards Western Europe. Therefore it is important to develop tools to improve our understanding of the spread and control of ASF for contingency planning. A stochastic and dynamic spatial spread model (DTU-DADS) was adjusted to simulate the spread of ASF virus between domestic swine herds exemplified by the Danish swine population. ASF was simulated to spread via animal movement, low- or medium-risk contacts and local spread. Each epidemic was initiated in a randomly selected herd − either in a nucleus herd, a sow herd, a randomly selected herd or in multiple herds simultaneously. A sensitivity analysis was conducted on input parameters. Given the inputs and assumptions of the model, epidemics of ASF in Denmark are predicted to be small, affecting about 14 herds in the worst-case scenario. The duration of an epidemic is predicted to vary from 1 to 76 days. Substantial economic damages are predicted, with median direct costs and export losses of €12 and €349 million, respectively, when epidemics were initiated in multiple herds. Each infectious herd resulted in 0 to 2 new infected herds varying from 0 to 5 new infected herds, depending on the index herd type.


      PubDate: 2016-08-04T20:13:02Z
       
  • TolC is important for bacterial survival and oxidative stress response in
           Salmonella enterica serovar Choleraesuis in an acidic environment
    • Abstract: Publication date: Available online 4 August 2016
      Source:Veterinary Microbiology
      Author(s): Jen-Jie Lee, Ying-Chen Wu, Chih-Jung Kuo, Shih-Ling Hsuan, Ter-Hsin Chen
      The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis.


      PubDate: 2016-08-04T20:13:02Z
       
  • Absence of co-localization between pathovar-associated virulence factors
           and extended-spectrum β-lactamase (blaCTX-M) genes on a single plasmid
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Charlotte Valat, Karine Forest, Méganne Billet, Charlène Polizzi, Estelle Saras, Jean-Yves Madec, Marisa Haenni
      Extended-spectrum β-lactamases (ESBLs) were reported in virulent food-borne Escherichia coli clones, and numerous genes encoding ESBLs and virulence factors (VFs) are plasmid-mediated. We investigated the plasmidic co-localization of ESBL genes and pathovar-associated VF genes isolated in 18 E. coli isolates from faecal samples of diseased cattle. From the rare ESBL-producing E. coli among the various pathovars, no plasmid co-localization was found between VF and bla CTX-M genes on a single plasmid. However, a link between replicon types and VFs was highlighted: EspP was associated with IncFIB and ToxB with IncB/O. Associations of IncF alleles to VF or CTX-M-types were also identified: CS31A was linked to the allele FIB38 and CTX-M-14 to IncFII2. Also, as illustrated here, IncFII and IncFIB were carried by two different plasmids in a single cell.


      PubDate: 2016-07-29T19:47:54Z
       
  • The effect of Tembusu virus Infection in Different Week-Old Cherry Valley
           Breeding Ducks
    • Abstract: Publication date: Available online 25 July 2016
      Source:Veterinary Microbiology
      Author(s): Yunjian Lu, Yanguo Dou, Jinfeng Ti, Aihua Wang, Binghua Cheng, Xin Zhang, Youxiang Diao
      To study the effect of Tembusu virus (TMUV) infection on Cherry Valley Breeding ducks of different ages, 350 five-week-old ducks were divided into 14 groups. Ducks in seven experimental group were respectively infected with 1.265×105 mean embryo lethal dose (ELD50) of TMUV-AHQY strain (in 4.2mL) by intravenous route. Ducks in control groups were inoculated with Phosphate-buffered Saline (PBS) in the same way. Clinical symptoms, gross and microscopic lesions, viral loads and serum antibodies were detected and recorded for 20days after infection. Some ducks infected at 7 and 21 week s of age showed severe clinical symptoms including depression and inappetence, and no obvious clinical symptoms were seen in other week-old infected ducks. Severe gross lesions including hepatomegaly, meningeal congestion, myocardial hemorrhage, intestinal, myocardial and pulmonary edema were observed in ducks infected at 7, 18 and 21 weeks of age. No or mild gross lesions were observed in ducks infected at 14 and 16 weeks of age. The main microscopic lesions including hyperaemia, degeneration and necrosis of different cells and inflammatory cellular infiltration mainly consisting of mononuclear cells or lymphocytes were observed in ducks infected at 7 and 21 week of age. But relatively intact structures and rare lymphocytic infiltration were presented in ducks infected at 14 and 16 weeks of age. Viral antigen was more frequently observed in organ slices collected from 7 week-old infected ducks and few positive staining was found in 14 and 16 week-old infected ducks. Less viral loads in different tissues and swabs were detected by a quantitative real-time PCR assay. The level of viral loads in the tissues of ducks infected at 14 and 16 weeks of age was very lower than that of ducks infected at 7 and 21 weeks of age. Meanwhile, less viral copy numbers were detected in swab samples collected from 14 and 16 week-old infected ducks. Ducks infected at 14-week-old developed significantly higher serum neutralizing antibody titers than those infected at other week of age. These results indicated that the effect of TMUV infection on Cherry Valley ducks is partly related to weeks of age. 7∼10 week-old and 18∼21 week-old ducks were more susceptible to TMUV infection, but 14∼16 week-old ducks were more resistant to this disease.


      PubDate: 2016-07-29T19:47:54Z
       
  • Infectivity of a recombinant murine norovirus (RecMNV) in Balb/cByJ mice
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Elisabeth Mathijs, Edmilson F. de Oliveira-Filho, Fabiana Dal Pozzo, Axel Mauroy, Damien Thiry, François Massart, Claude Saegerman, Etienne Thiry
      The infectivity of a recombinant murine norovirus (RecMNV) strain, previously isolated following in vitro coinfections, was evaluated in vivo in comparison with its parental strains (MNV-1-CW1 and WU20) in Balb/cByJ mice via measurement of weight loss and estimation of viral loads in faeces, tissues and organs 48 and 72h post-infection. The presence of infectious virus in all analysed tissues and organs suggests that, similarly to its parental viruses, RecMNV can disseminate beyond organs associated with the digestive tract. Our results also suggest that recombination occurring in vitro between two homologous murine norovirus strains can give rise to a chimeric strain which, despite slight differences, shows similar biological properties to its parental strains. This study provides the first report on in vivo replication of a recombinant norovirus strain isolated following in vitro coinfection. These results have great significance for norovirus genetic evolution and future vaccine development.


      PubDate: 2016-07-29T19:47:54Z
       
  • Wild boars harboring porcine epidemic diarrhea virus (PEDV) may play an
           important role as a PEDV reservoir
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Dong Uk Lee, Taeyong Kwon, Sang H. Je, Sung J. Yoo, Sang Won Seo, Sun Young Sunwoo, Young S. Lyoo
      Porcine epidemic diarrhea virus (PEDV) is a burdensome pathogen in the swine industry. Wild boar population poses a high risk for reservoir of viral pathogen. Two hundred eighty seven samples from wild boar (Sus scrofa) collected in South Korea during 2010/11 were analyzed using RT-PCR, revealing a PEDV infection rate of 9.75% (28/287). PEDV positive samples were distributed throughout the mainland of South Korea, clustering at the northern border adjacent to the Demilitarized Zone (DMZ) and in mountainous regions. PEDV in wild boar was genetically similar to Chinese PEDV strains in phylogenetic investigations. Our results indicated that PEDV is circulating in the wild boar and provided a novel knowledge into epidemiology of PEDV infection.


      PubDate: 2016-07-29T19:47:54Z
       
  • Reassortant H5N1 avian influenza viruses containing PA or NP gene from an
           H9N2 virus significantly increase the pathogenicity in mice
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Xiaoli Hao, Jiao Hu, Jiongjiong Wang, Jing Xu, Hao Cheng, Yunpeng Xu, Qunhui Li, Dongchang He, Xiaowen Liu, Xiaoquan Wang, Min Gu, Shunlin Hu, Xiulong Xu, Huimou Liu, Sujuan Chen, Daxin Peng, Xiufan Liu
      Reassortment between different influenza viruses is a crucial way to generate novel influenza viruses with unpredictable virulence and transmissibility, which may threaten the public health. As currently in China, avian influenza viruses (AIVs) of H9N2 and H5N1 subtypes are endemic in poultry in many areas, while they are prone to reassort with each other naturally. In order to evaluate the risk of the reassortment to public health, A/Goose/Jiangsu/k0403/2010 [GS/10(H5N1)] virus was used as a backbone to generate a series of reassortants, each contained a single internal gene derived from the predominant S genotype of the A/Chicken/Jiangsu/WJ57/2012 [WJ/57(H9N2)]. We next assessed the biological characteristics of these assortments, including pathogenicity, replication efficiency and polymerase activity. We found that the parental WJ/57(H9N2) and GS/10(H5N1) viruses displayed high genetic compatibility. Notably, the H5N1 reassortants containing the PA or NP gene from WJ/57(H9N2) virus significantly increased virulence and replication ability in mice, as well as markedly enhanced polymerase activity. Our results indicate that the endemicity of H9N2 and H5N1 in domestic poultry greatly increases the possibility of generating new viruses by reassortment that may pose a great threat to poultry industry and public health.


      PubDate: 2016-07-29T19:47:54Z
       
  • Maternally-derived antibodies (MDAs) impair piglets’ humoral and
           cellular immune responses to vaccination against porcine reproductive and
           respiratory syndrome (PRRS)
    • Abstract: Publication date: Available online 25 July 2016
      Source:Veterinary Microbiology
      Author(s): C. Fablet, P. Renson, F. Eono, S. Mahé, E. Eveno, M. Le Dimna, V. Normand, A. Lebret, N. Rose, O. Bourry
      The influence of maternally-derived antibodies (MDAs) on the post-vaccination humoral and cellular immune responses in piglets vaccinated against PRRS was studied. The piglets came from a vaccinated breeding herd. Thirty piglets with a low (A-) or high level (A+) of PRRSV-neutralizing MDAs were vaccinated (V+) with a modified live vaccine at 3 weeks of age. Blood samples were collected before vaccination and then at 2, 4, 8 and 14 weeks post-vaccination (WPV). The samples were analysed to detect the vaccine viraemia (RT-PCR) and quantify the post-vaccination humoral (ELISA and virus neutralisation test) and cellular (ELISPOT IFNɣ) immune responses. PRRSV vaccine strain was detected in 60%, 64%, 36% and 0% of A-V+ piglets 2, 4, 8 and 14 WPV respectively. No virus was detected in A+V+ piglets during the first four WPV but 32% and 6% of A+V+ piglets were PCR-positive at 8 and 14 WPV. Eighty-five percent of A-V+ piglets and 0% of A+V+ piglets seroconverted (ELISA) between 2 and 4 WPV. Neutralising antibodies appeared 4 WPV in the A-V+ piglets and 14 WPV in the A+V+ piglets. The number of PRRSV-specific IFNɣ-secreting cells was significantly higher in A-V+ piglets at 2 and 4 WPV than in A+V+ piglets. These results show that MDAs can affect both post-vaccination humoral and cellular immune responses in piglets. Further studies are required to assess the impact of MDAs on vaccine efficacy following a PRRSV challenge and its ability to reduce viral transmission.


      PubDate: 2016-07-29T19:47:54Z
       
  • Chasing Salmonella Typhimurium in free range egg production system
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Kapil Chousalkar, Vaibhav Gole, Charles Caraguel, Jean-Loup Rault
      Free range production systems are becoming a major source of egg production in Australia and worldwide. This study investigated shedding and ecology of Salmonella Typhimurium and Salmonella species in a free range layer flock, wild birds and foxes in the vicinity of the free range farm in different seasons. Shedding of Salmonella was significantly higher in summer. Within the shed, overall, Salmonella prevalence was highest in dust. Corticosterone level in faeces was highest in spring and lowest in winter. There was no direct association between the Salmonella shedding (MPN/gm) and corticosterone levels in faeces. Salmonella Typhimurium MLVA types isolated from fox and wild birds were similar to MLVA types isolated from layer flock and reported during human food borne illness. Wild birds and foxes appear to play an important role in S. Typhimurium ecology and food safety. Environmental factors could play a role in evolution of S. Typhimurium in free range environment.


      PubDate: 2016-07-29T19:47:54Z
       
  • Observations on macrolide resistance and susceptibility testing
           performance in field isolates collected from clinical bovine respiratory
           disease cases
    • Abstract: Publication date: Available online 26 July 2016
      Source:Veterinary Microbiology
      Author(s): Keith D. DeDonder, Dayna M. Harhay, Michael D. Apley, Brian V. Lubbers, Michael L. Clawson, Gennie Schuller, Gregory P. Harhay, Brad J. White, Robert L. Larson, Sarah F. Capik, Jim E. Riviere, Ted Kalbfleisch, Ronald K. Tessman
      The objectives of this study were; first, to describe gamithromycin susceptibility of Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni isolated from cattle diagnosed with bovine respiratory disease (BRD) and previously treated with either gamithromycin for control of BRD (mass medication=MM) or sham-saline injected (control=CON); second, to describe the macrolide resistance genes present in genetically typed M. haemolytica isolates; third, use whole-genome sequencing (WGS) to correlate the phenotypic resistance and genetic determinants for resistance among M. haemolytica isolates. M. haemolytica (n=276), P. multocida (n=253), and H. somni (n=78) were isolated from feedlot cattle diagnosed with BRD. Gamithromycin susceptibility was determined by broth microdilution. Whole-genome sequencing was utilized to determine the presence/absence of macrolide resistance genes and to genetically type M. haemolytica. Generalized linear mixed models were built for analysis. There was not a significant difference between MM and CON groups in regards to the likelihood of culturing a resistant isolate of M. haemolytica or P. multocida. The likelihood of culturing a resistant isolate of M. haemolytica differed significantly by state of origin in this study. A single M. haemolytica genetic subtype was associated with an over whelming majority of the observed resistance. H. somni isolation counts were low and statistical models would not converge. Phenotypic resistance was predicted with high sensitivity and specificity by WGS. Additional studies to elucidate the relationships between phenotypic expression of resistance/genetic determinants for resistance and clinical response to antimicrobials are necessary to inform judicious use of antimicrobials in the context of relieving animal disease and suffering.


      PubDate: 2016-07-29T19:47:54Z
       
  • Cross reactivity among the swine mycoplasmas as identified by protein
           microarray
    • Abstract: Publication date: Available online 28 July 2016
      Source:Veterinary Microbiology
      Author(s): Andrew C. Petersen, David C. Oneal, Janice R. Seibel, Kylie Poel, Courtney L. Daum, Steven P. Djordjevic, F. Chris Minion
      Mycoplasmas are cell wall-less bacteria that infect a variety of animals in a species-specific manner. In swine, Mycoplasma hyopneumoniae is the most virulent and presents the most disease and economic problems to the swine industry. Serological assays are commonly used to assess colonization and disease, but antigenic cross-reactivity between M. hyopneumoniae and other mycoplasma species, most notably M. hyorhinis, M. hyosynoviae and M. flocculare, is a concern. The extent of cross-reactivity has not been thoroughly investigated. These studies were designed to identify M. hyopneumoniae proteins that are recognized by rabbit hyperimmune sera raised against the other swine mycoplasmas. Our results indicate extensive cross-reactivity between M. flocculare and M. hyopneumoniae, which explains previous reports seen with ELISA assays. Only three of the thirty-nine M. hyopneumoniae proteins tested showed no cross reactivity with the other three swine mycoplasmas, mhp182 (42kDa C-terminal fragment), mhp638 and mhp684 (C-terminal fragment). Two proteins, mhp384 and mhp511, were cross-reactive with hyperimmune sera generated against three of the four species. None of the anti-M. hyorhinis hyperimmune sera reacted to any of the M. hyopneumoniae proteins. These results suggest that inapparent M. flocculare infections could produce positive responses in M. hyopneumoniae serological assays due to cross-reactivity, and that M. hyosynoviae infections are less likely to do so and M. hyorhinis infections unlikely to affect assay results.


      PubDate: 2016-07-29T19:47:54Z
       
  • Candida tropicalis from veterinary and human sources shows similar in
           vitro hemolytic activity, antifungal biofilm susceptibility and
           pathogenesis against Caenorhabditis elegans
    • Abstract: Publication date: Available online 28 July 2016
      Source:Veterinary Microbiology
      Author(s): Raimunda Sâmia Nogueira Brilhante, Jonathas Sales de Oliveira, Antônio José de Jesus Evangelista, Rosana Serpa, Aline Lobão da Silva, Felipe Rodrigues Magalhães de Aguiar, Vandbergue Santos Pereira, Débora de Souza Collares Maia Castelo-Branco, Waldemiro Aquino Pereira-Neto, Rossana de Aguiar Cordeiro, José Júlio Costa Sidrim, Marcos Fábio Gadelha Rocha
      The aim of this study was to evaluate the in vitro hemolytic activity and biofilm antifungal susceptibility of veterinary and human Candida tropicalis strains, as well as their pathogenesis against Caenorhabditis elegans. Twenty veterinary isolates and 20 human clinical isolates of C. tropicalis were used. The strains were evaluated for their hemolytic activity and biofilm production. Biofilm susceptibility to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin was assessed using broth microdilution assay. The in vivo evaluation of strain pathogenicity was investigated using the nematode C. elegans. Hemolytic factor was observed in 95% of the strains and 97.5% of the isolates showed ability to form biofilm. Caspofungin and amphotericin B showed better results than azole antifungals against mature biofilms. Paradoxical effect on mature biofilm metabolic activity was observed at elevated concentrations of caspofungin (8–64μg/mL). Azole antifungals were not able to inhibit mature C. tropicalis biofilms, even at the higher tested concentrations. High mortality rates of C. elegans were observed when the worms were exposed to with C. tropicalis strains, reaching up to 96%, 96h after exposure of the worms to C. tropicalis strains. These results reinforce the high pathogenicity of C. tropicalis from veterinary and human sources and show the effectiveness of caspofungin and amphotericin B against mature biofilms of this species.


      PubDate: 2016-07-29T19:47:54Z
       
  • Experimental infection of small ruminants with bluetongue virus expressing
           Toggenburg Orbivirus proteins
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Piet A. van Rijn, Sandra G.P. van de Water, Mieke A. Maris-Veldhuis, René G.P. van Gennip
      Bluetongue virus (BTV) is the prototype orbivirus (Reoviridae family, genus Orbivirus) consisting of more than 24 recognized serotypes or neutralization groups. Recently, new BTV serotypes in goats have been found; serotype 25 (Toggenburg Orbivirusor TOV), serotype 26 (KUW2010/02), and serotype 27 from Corsica, France. KUW2010/02 has been isolated in mammalian cells but is not replicating in Culicoides cells. TOVhas been detected in goats but could not been cultured, although TOV has been successfully passed to naïve animals by experimental infection using viremic blood. Genome segments Seg-2[VP2], Seg-6[VP5], Seg-7[VP7], and Seg-10[NS3/NS3a] expressing the respective TOV proteins were incorporated in BTV using reverse genetics, demonstrating that these TOV proteins are functional in BTV replication. Depending on the incorporated TOV proteins, in vitro replication is, however, decreased compared to the ancestor BTV, in particular by TOV-VP5. Sheep and goats were experimentally infected with BTV expressing both outer capsid proteins VP2 and VP5 of TOV, so-named ‘TOV-serotyped BTV’. Viremia was not detected in sheep, and hardly detected in goats after infection with TOV-serotyped BTV. Seroconversion by cELISA, however, was detected, suggesting that TOV-serotyped BTV replicates in small ruminants. One goat was coincidentally pregnant, and the fetus was strong PCR-positive in blood samples and several organs, which conclusively demonstrates that TOV-serotyped BTV replicates in vivo.


      PubDate: 2016-07-29T19:47:54Z
       
  • Low proviral small ruminant lentivirus load as biomarker of natural
           restriction in goats
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Helena Crespo, Luigi Bertolotti, Margherita Proffiti, Paolo Cascio, Fulvia Cerruti, Pier Luigi Acutis, Damián de Andrés, Ramsés Reina, Sergio Rosati
      Small ruminant lentiviruses (SRLV) globally affect welfare and production of sheep and goats and are mainly controlled through elimination of infected animals, independently of the viral kinetics within the single animal. Control programs are based on highly sensitive serological tests, however the existence of low antibody responders leads to the permanent presence of seronegative infected animals in the flock, thus perpetuating the infection. On the other hand, long-term non-progressors show a detectable antibody response not indicative of a shedding animal, suggesting immune contention of infection. In this study, we analyse two goat populations within the same herd, harbouring low or high proviral SRLV loads respectively, both showing a robust antibody response. In vivo findings were confirmed in vitro since fibroblastic cell lines obtained from one high and one low proviral load representative goats, showed respectively a high and a faint production of virus upon infection with reference and field circulating SRLV strains. Differences in virus production were relieved when strain CAEV-Co was used for experimental infection. We analysed LTR promoter activity, proviral load, entry step and production of virus and viral proteins. Intriguingly, proteasomal activity was higher in fibroblasts from low proviral load animals and proteasome inhibition increased viral production in both cell lines, suggesting the implication of active proteasome-dependent restriction factors. Among them, we analysed relative expression and sequences of TRIM5α, APOBEC3 (Z1, Z2, Z3 and Z2-Z3) and BST-2 (Tetherin) and found a global antiviral status in low proviral carriers that may confer protection against viral shedding and disease onset.


      PubDate: 2016-07-29T19:47:54Z
       
  • In vitro invasive capacity of Salmonella strains into sections of the
           layer hen oviduct
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Andrea R. McWhorter, Kapil K. Chousalkar
      Raw or undercooked eggs and egg products are frequently identified as the source of Salmonella following outbreaks of foodborne gastrointestinal disease. Some Salmonella serovars, such as Salmonella Enteriditis, have a high tropism for the oviduct of laying hens. Oviduct colonization with S. Enteriditis can result in both internal and external contamination of an egg. While oviduct invasion is not limited to S. Enteriditis, the invasive capacities of other serovars is not widely known. In this study, the in vitro invasive ability of eighteen Salmonella isolates of representative serovars into different segments of the oviduct was assessed. All Salmonella isolates tested were invasive and the highest bacterial invasion was observed in segments of the isthmus and vagina. S. Bredeney consistently exhibited the lowest invasion into all sections of the oviduct. Interestingly, the S. Typhimurium definitive types included in this study did not exhibit significantly greater invasion capacity than other serovars. In this study, the genomic capacity of the selected isolates of representative Salmonella serovars to colonize the layer hen oviduct was also investigated. Previous studies have identified several genes upregulated during oviduct colonization by S. Enteriditis. Single gene comparison of 107 genes from eleven Salmonella isolates was conducted to determine whether these oviduct colonization genes were present within each bacterial genome. The degree of homology with corresponding sequences in S. Enteriditis P125109 was also determined for each gene. Genes encoding the O-antigen as well as phage and virulence plasmid genes were among the most highly variable and may serve specific roles in oviduct invasion.


      PubDate: 2016-07-29T19:47:54Z
       
  • Molecular characterization of a feline calicivirus isolated from tiger and
           its pathogenesis in cats
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Jin Tian, Dafei Liu, Yongxiang Liu, Hongxia Wu, Yanmei Jiang, Shaopo Zu, Chunguo Liu, Xue Sun, Jiasen Liu, Liandong Qu
      Feline calicivirus (FCV) is a virus that causes respiratory disease in cats. In this study, the FCV TIG-1 was isolated from Siberian tiger feces collected in 2014 in Heilongjiang Province, China. Phylogenetic analysis among TIG-1 and other FCVs showed that TIG-1 does not share the same lineage with other FCV isolates from Heilongjiang or other regions in China but is located in the same cluster with the FCV strain Urbana, which was isolated from the United States. The growth kinetics in vitro and the pathogenicity in cats between TIG-1 and the domestic cat-origin FCV strain F9 (vaccine strain) and strain 2280 were compared. We found that the growth kinetics of strains TIG-1 and 2280 were faster than that of strain F9 from 12h to 36h post-infection, indicating that strains TIG-1 and 2280 produce infectious virions and reach peak yields earlier. Challenge experiments in cats showed that TIG-1 grew faster than the other two strains in the lungs of cats and that TIG-1 is a virulent FCV with 100% morbidity and lethality. In addition, the histopathological results showed that the virulent TIG-1 strain directly led to severe lung tissue damage and indirectly led to intestinal damage. The results presented here show that a tiger-origin FCV exhibits high virulence in cats.


      PubDate: 2016-07-29T19:47:54Z
       
  • Sequence adaptations during growth of rescued classical swine fever
           viruses in cell culture and within infected pigs
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Johanne Hadsbjerg, Martin B. Friis, Ulrik Fahnøe, Jens Nielsen, Graham J. Belsham, Thomas Bruun Rasmussen
      Classical swine fever virus (CSFV) causes an economically important disease of swine. Four different viruses were rescued from full-length cloned cDNAs derived from the Paderborn strain of CSFV. Three of these viruses had been modified by mutagenesis (with 7 or 8 nt changes) within stem 2 of the subdomain IIIf of the internal ribosome entry site (IRES) that directs the initiation of protein synthesis. Rescued viruses were inoculated into pigs. The rescued vPader10 virus, without modifications in the IRES, induced clinical disease in pigs that was very similar to that observed previously with the parental field strain and transmission to in-contact pigs occurred. Two sequence reversions, in the NS2 and NS5B coding regions, became dominant within the virus populations in these infected pigs. Rescued viruses, with mutant IRES elements, did not induce disease and only very limited circulation of viral RNA could be detected. However, the animals inoculated with these mutant viruses seroconverted against CSFV. Thus, these mutant viruses were highly attenuated in vivo. All 4 rescued viruses were also passaged up to 20 times in cell culture. Using full genome sequencing, the same two adaptations within each of four independent virus populations were observed that restored the coding sequence to that of the parental field strain. These adaptations occurred with different kinetics. The combination of reverse genetics and in depth, full genome sequencing provides a powerful approach to analyse virus adaptation and to identify key determinants of viral replication efficiency in cells and within host animals.


      PubDate: 2016-07-29T19:47:54Z
       
  • Inactivated porcine reproductive and respiratory syndrome virus vaccine
           adjuvanted with Montanide™ Gel 01 ST elicits virus-specific
           cross-protective inter-genotypic response in piglets
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Kairat Tabynov, Abylay Sansyzbay, Zhanara Tulemissova, Kaissar Tabynov, Santosh Dhakal, Aigul Samoltyrova, Gourapura J. Renukaradhya, Muratbay Mambetaliyev
      The efficacy of a novel BEI-inactivated porcine reproductive and respiratory syndrome virus (PRRSV) candidate vaccine in pigs, developed at RIBSP Republic of Kazakhstan and delivered with an adjuvant Montanide™ Gel 01 ST (D/KV/ADJ) was compared with a commercial killed PRRSV vaccine (NVDC-JXA1, C/KV/ADJ) used widely in swine herds of the Republic of Kazakhstan. Clinical parameters (body temperature and respiratory disease scores), virological and immunological profiles [ELISA and virus neutralizing (VN) antibody titers], macroscopic lung lesions and viral load in the lungs (quantitative real-time PCR and cell culture assay) were assessed in vaccinated and both genotype 1 and 2 PRRSV challenged pigs. Our results showed that the commercial vaccine failed to protect pigs adequately against the clinical disease, viremia and lung lesions caused by the challenged field isolates, Kazakh strains of PRRSV type 1 and type 2 genotypes. In contrast, clinical protection, absence of viremia and lung lesions in D/KV/ADJ vaccinated pigs was associated with generation of VN antibodies in both homologous vaccine strain LKZ/2010 (PRRSV type 2) and a heterogeneous type 1 PRRSV strain (CM/08) challenged pigs. Thus, our data indicated the induction of cross-protective VN antibodies by D/KV/ADJ vaccine, and importantly demonstrated that an inactivated PRRSV vaccine could also induce cross-protective response across the viral genotype.


      PubDate: 2016-07-29T19:47:54Z
       
  • Evaluation of a 20year old porcine reproductive and respiratory syndrome
           (PRRS) modified live vaccine (Ingelvac® PRRS MLV) against two recent type
           2 PRRS virus isolates in South Korea
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Jiwoon Jeong, Kyuhyung Choi, Ikjae Kang, Changhoon Park, Chanhee Chae
      Type 2 porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) was first isolated in Korea in 1994. The commercial PRRS modified live vaccine (Ingelvac® PRRS MLV, Boehringer Ingelheim Vetmedica Inc., St. Joseph, Missouri, USA) based on type 2 PRRSV, was first licensed for use in 3- to 18-week-old pigs in Korea in 1996. The objective of the present study was to evaluate the efficacy of this 20year old commercial PRRS modified live vaccine (MLV) against two recent PRRSV isolates. Two genetically distant type 2 PRRSV strains (SNUVR150004 for lineage 1 and SNUVR150324 for lineage 5), isolated in 2015, were used as challenge virus. Regardless of the challenge virus, vaccination of pigs effectively reduced the level of viremia, the lung lesions, and of the PRRSV antigen within the lung lesions. The induction of virus-specific interferon-γ secreting cells by the PRRS vaccine produced a protective immune response, leading to the reduction of PRRSV viremia. There were no significant differences in efficacy against the two recently isolated viruses by the PRRS MLV based on virological results, immunological responses, and pathological outcomes. This study demonstrates that the PRRS MLV used in this study is still effective against recently isolated heterologous type 2 PRRSV strains even after 20 years of use in over 35 million pigs


      PubDate: 2016-07-29T19:47:54Z
       
  • Characterization of Pajaroellobacter abortibovis, the etiologic agent of
           epizootic bovine abortion
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Roxann S. Brooks, Myra T. Blanchard, Kristin A. Clothier, Scott Fish, Mark L. Anderson, Jeffery L. Stott
      Epizootic bovine abortion (EBA), first identified in the 1950s, is a major contributor of economic loss to western U.S. beef producers. The causative agent proved elusive for over fifty years until a novel Deltaproteobacteria was identified as the etiologic agent in 2005. The microbe, which has yet to be successfully cultured in vitro, has proven difficult to purify from necropsy tissues. Thus, phylogenetic characterization has been limited to analysis of the 16S ribosomal RNA (rRNA) gene (AF503916), which placed this bacterium in the order Myxococcales, suborder Sorangiineae, family Polyangiaceae and most closely related to Sorangium cellulosum. The focus of the current study was to further expand the morphologic characterization and taxonomic placement of this bacteria, named here as Pajaroellobacter abortibovis. Modified Gram staining, combined with transmission electron microscopy, provide strong evidence that the bacterium is gram negative. Flow cytometric analysis identified the presence of P. abortibovis in murine leukocytes. While attempts to sequence ten universally conserved protein-coding genes using previously published degenerative primers failed, redesigned primers based solely upon Deltaproteobacteria facilitated the partial sequencing of two genes; fusA (JQ173112) and pyrG (JQ173111). Primers designed in a similar fashion generated a partial sequence of the 23S rRNA gene (JQ173113) These sequences, combined with a revised 16S rRNA phylogenic analysis, support the placement of this bacteria as a unique genus separate from Sorangium.


      PubDate: 2016-07-29T19:47:54Z
       
  • The role of Ca2+ mediated signaling pathways on the effect of taurine
           against Streptococcus uberis infection
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Bin Dai, Jinqiu Zhang, Ming Liu, Jinye Lu, Yuanshu Zhang, Yuanyuan Xu, Jinfeng Miao, Yulong Yin
      To provide insight into the mechanisms of taurine attenuation of pro-inflammatory response in mouse mammary epithelial cell line (EpH4-Ev, purchased by ATCC, USA) after Streptococcus uberis (S. uberis, 0140J) challenge, we infected MECs with S. uberis (2.5×107 cfumL−1, MOI=10) for 3h and quantified changes in TLR-2 and calcium (Ca2+) mediated signaling pathways. The results indicate that S. uberis infection significantly increases the expression of TLR-2, intracellular Ca2+ levels, PLC-γ1 and PKC-α, the activities of transcription factors NF-κB and NFAT, and related cytokines (TNF-α, IL-1β, IL-6, G-CSF, IL-2, KC, IL-15, FasL, MCP-1, and LIX) in culture supernatants. Taurine administration downregulated all these indices, the activities of NF-κB and NFAT. Cytokine secretions were similar using special PKC inhibitor Go 6983 and NFAT inhibitor VIVIT. Our data indicate that S. uberis infection induces pro-inflammatory response of MECs through a TLR-2 mediated signaling pathway. In addition, taurine can prevent MEC damage by affecting both PLC-γ1-Ca2+-PKC-α-NF-κB and PLC-γ1-Ca2+-NFATs signaling pathways. This is the first report to demonstrate the mechanisms of taurine attenuated pro-inflammatory response in MECs after S. uberis challenge.


      PubDate: 2016-07-29T19:47:54Z
       
  • Molecular surveillance of traditional and emerging pathogens associated
           with canine infectious respiratory disease
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Nicola Decaro, Viviana Mari, Vittorio Larocca, Michele Losurdo, Gianvito Lanave, Maria Stella Lucente, Marialaura Corrente, Cristiana Catella, Stefano Bo, Gabriella Elia, Giorgio Torre, Erika Grandolfo, Vito Martella, Canio Buonavoglia
      A molecular survey for traditional and emerging pathogens associated with canine infectious respiratory disease (CIRD) was conducted in Italy between 2011 and 2013 on a total of 138 dogs, including 78 early acute clinically ill CIRD animals, 22 non-clinical but exposed to clinically ill CIRD dogs and 38 CIRD convalescent dogs. The results showed that canine parainfluenza virus (CPIV) was the most commonly detected CIRD pathogen, followed by canine respiratory coronavirus (CRCoV), Bordetella bronchiseptica, Mycoplasma cynos, Mycoplasma canis and canine pneumovirus (CnPnV). Some classical CIRD agents, such as canine adenoviruses, canine distemper virus and canid herpesvirus 1, were not detected at all, as were not other emerging respiratory viruses (canine influenza virus, canine hepacivirus) and bacteria (Streptococcus equi subsp. zooepidemicus). Most severe forms of respiratory disease were observed in the presence of CPIV, CRCoV and M. cynos alone or in combination with other pathogens, whereas single CnPnV or M. canis infections were detected in dogs with no or very mild respiratory signs. Interestingly, only the association of M. cynos (alone or in combination with either CRCoV or M. canis) with severe clinical forms was statistically significant. The study, while confirming CPIV as the main responsible for CIRD occurrence, highlights the increasing role of recently discovered viruses, such as CRCoV and CnPnV, for which effective vaccines are not available in the market.


      PubDate: 2016-07-29T19:47:54Z
       
  • Equine herpesvirus type 1 modulates inflammatory host immune response
           genes in equine endothelial cells
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Stephanie Johnstone, Jekaterina Barsova, Isabel Campos, Arthur R. Frampton
      Equine herpesvirus myeloencephalopathy (EHM), a disease caused by equine herpesvirus type 1 (EHV-1), is characterized by severe inflammation, thrombosis, and hypoxia in central nervous system (CNS) endothelial cells, which can result in a spectrum of clinical signs including urinary incontinence, ataxia, and paralysis. Strains of EHV-1 that contain a single point mutation within the viral DNA polymerase (nucleotide A2254 >G2254: amino acid N752 →D752) are isolated from EHM afflicted horses at higher frequencies than EHV-1 strains that do not harbor this mutation. Due to the correlation between the DNA Pol mutation and EHM disease, EHV-1 strains that contain the mutation have been designated as neurologic. In this study, we measured virus replication, cell to cell spread efficacy, and host inflammatory responses in equine endothelial cells infected with 12 different strains of EHV-1. Two strains, T953 (Ohio 2003) (neurologic) and Kentucky A (KyA) (non-neurologic), have well described disease phenotypes while the remaining strains used in this study are classified as neurologic or non-neurologic based solely on the presence or absence of the DNA pol mutation, respectively. Results show that the neurologic strains do not replicate better or spread more efficiently in endothelial cells. Also, the majority of the host inflammatory genes were modulated similarly regardless of EHV-1 genotype. Analyses of host gene expression showed that a subset of pro-inflammatory cytokines, including the CXCR3 ligands CXCL9, CXCL10, and CXCL11, as well as CCL5, IL-6 and TNF-α were consistently up-regulated in endothelial cells infected with each EHV-1 strain. The identification of specific pro-inflammatory cytokines in endothelial cells that are modulated by EHV-1 provides further insight into the factors that contribute to the immunopathology observed after infection and may also reveal new targets for disease intervention.


      PubDate: 2016-07-29T19:47:54Z
       
  • The impact of the LuxS mutation on phenotypic expression of factors
           critical for Campylobacter jejuni colonization
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Kathy T. Mou, Paul J. Plummer
      Studies have collectively shown the wide impact that luxS mutation has on the expression and function of various aspects of Campylobacter jejuni virulence. Previous work from our group demonstrated that LuxS mutagenesis negatively impacts colonization of the gastrointestinal tract of several host species. To determine what is responsible for the colonization defect, we used a mechanistic approach to understand how the luxS mutation affects the expression of key physiologic factors important to the colonization ability of C. jejuni. This included expression of genes from the CmeABC efflux system, cell morphology, and motility through mucin substrate between wildtype, luxS mutant, and luxS complement of the C. jejuni strains 11168 and/or IA3902. We also measured and compared the activated methyl cycle (AMC) metabolite levels of the IA3902 luxS mutant to wildtype. Results showed that mutagenesis of the luxS gene completely disrupted the AMC with altered concentrations of AMC metabolites both upstream and downstream of LuxS. Multidrug efflux pump genes cmeABC and cmeR showed no significant changes in expression levels within the luxS mutant. Though motility through mucin was not completely unaffected by the luxS mutation, the lack of differences in cell morphology between wildtype and luxS mutant suggest that morphology is not responsible for the slight changes in mucin penetration observed in one of our luxS mutants. Though additional studies are warranted, these findings suggest that the CmeABC multi-drug efflux pump, cell morphology and mucin penetration are not major mechanisms responsible for the luxS mutant’s colonization defect in its host.


      PubDate: 2016-07-29T19:47:54Z
       
  • Estimating the incidence of equine viral arteritis and the sensitivity of
           its surveillance in the French breeding stock
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): J.P. Amat, T. Vergne, J. Tapprest, B. Ferry, A. Hans, P. Hendrikx, B. Dufour, A. Leblond
      Equine viral arteritis (EVA) may have serious economic impact on the equine industry. For this reason, it is monitored in many countries, especially in breeding stock, to avoid its spread during breeding activities. In France, surveillance is mainly based on serological tests, since mares are not vaccinated, but difficulties in interpreting certain series of results may impair the estimation of the number of outbreaks. In this study, we propose specific rules for identifying seroconversion in order to estimate the number of outbreaks that were detected by the breeding stock surveillance component (BSSC) in France between 2006 and 2013. A consensus among multidisciplinary experts was reached to consider seroconversion as a change in antibody titer from negative to at least 32, or as an eight-fold or greater increase in antibody level. Using these rules, 239 cases and 177 outbreaks were identified. Subsequently, we calculated the BSSC’s sensitivity as the ratio of the number of detected outbreaks to the total number of outbreaks that occurred in breeding stock (including unreported outbreaks) estimated using a capture-recapture model. The total number of outbreaks was estimated at 215 (95% credible interval 195–249) and the surveillance sensitivity at 82% (CrI95% 71–91). Our results confirm EVA circulation in French breeding stock, show that neutralizing antibodies can persist up to eight years in naturally infected mares and suggest that certain mares have been reinfected. This study shows that the sensitivity of the BSSC is relatively high and supports its relevance to prevent the disease spreading through mating.


      PubDate: 2016-07-29T19:47:54Z
       
  • Impact of enrofloxacin and florfenicol therapy on the spread of OqxAB gene
           and intestinal microbiota in chickens
    • Abstract: Publication date: 30 August 2016
      Source:Veterinary Microbiology, Volume 192
      Author(s): Yi Chen, Jian Sun, Xiao-Ping Liao, Yang Shao, Liang Li, Liang-Xing Fang, Ya-Hong Liu
      Horizontal transfer of plasmid-encoded multidrug-resistant determinants is a major health problem and has attracted much public attention. We studied the dissemination of the efflux pump gene oqxAB located on transferable plasmid pHXY0908 between Salmonella Typhimurium and Escherichia coli in the gut of chickens. After an inoculation with Salmonella Typhimurium harboring oqxAB-bearing plasmid pHXY0908, chickens were treated with enrofloxacin and florfenicol. Inoculated, but non-treated chickens were included as a control group. Our results revealed that commensal E. coli isolates from the gut of chickens acquired the oqxAB-bearing plasmid in both treated and non-treated groups. Additionally, in the florfenicol treatment group, the average isolation rate of oqxAB-positive E. coli was significantly higher than that in the non-treated group. PFGE analysis showed that oqxAB-positive E. coli strains belonged to different patterns with one predominating. Moreover, multilocus sequence typing analysis revealed that E. coli ST533 was closely associated with the spread of oqxAB gene. qPCR analysis indicated that antibiotic administration provided selective advantages for sustaining a significantly high level of oqxAB gene from the DNA extracted from the feces. There was also a fluctuation in the intestinal microbiota with antibiotic therapy. In conclusion, the present study indicates that the oqxAB gene could be readily spread within the intestinal microflora. This could be enhanced by administrated with clinical doses of florfenicol and enrofloxacin, resulting in the enlargement of resistance gene reservoirs. In addition, ST533 E. coli isolates were found to contribute to transfer of the oqxAB gene.


      PubDate: 2016-07-29T19:47:54Z
       
  • Genetic and antigenic characterization of H5, H6 and H9 avian influenza
           viruses circulating in live bird markets with intervention in the center
           part of Vietnam
    • Abstract: Publication date: Available online 25 July 2016
      Source:Veterinary Microbiology
      Author(s): Duc-Huy Chu, Masatoshi Okamatsu, Keita Matsuno, Takahiro Hiono, Kohei Ogasawara, Lam Thanh Nguyen, Long Van Nguyen, Tien Ngoc Nguyen, Thuy Thu Nguyen, Dong Van Pham, Dang Hoang Nguyen, Tho Dang Nguyen, Thanh Long To, Hung Van Nguyen, Hiroshi Kida, Yoshihiro Sakoda
      A total of 3,045 environmental samples and oropharyngeal and cloacal swabs from apparently healthy poultry have been collected at three live bird markets (LBMs) at which practices were applied to reduce avian influenza (AI) virus transmission (intervention LBMs) and six conventional LBMs (non-intervention LBMs) in Thua Thien Hue province in 2014 to evaluate the efficacy of the intervention LBMs. The 178 AI viruses, including H3 (19 viruses), H4 (2), H5 (8), H6 (30), H9 (114), and H11 (5), were isolated from domestic ducks, muscovy ducks, chickens, and the environment. The prevalence of AI viruses in intervention LBMs (6.1%; 95% CI: 5.0 to 7.5) was similar to that in non-intervention LBMs (5.6%; 95% CI: 4.5 to 6.8; χ2 =0.532; df =1; P =0.53) in the study area. Eight H5N6 highly pathogenic avian influenza (HPAI) viruses were isolated from apparently healthy ducks, muscovy ducks, and an environmental sample in an intervention LBM. The hemagglutinin genes of the H5N6 HPAI viruses belonged to the genetic clade 2.3.4.4, and the antigenicity of the H5N6 HPAI viruses differed from the H5N1 HPAI viruses previously circulating in Vietnam. Phylogenetic and antigenic analyses of the H6 and H9 viruses isolated in both types of LBMs revealed that they were closely related to the viruses isolated from domestic birds in China, Group II of H6 viruses and Y280 lineage of H9 viruses. These results indicate that the interventions currently applied in LBMs are insufficient to control AI. A risk analysis should be conducted to identify the key factors contributing to AI virus prevalence in intervention LBMs.


      PubDate: 2016-07-29T19:47:54Z
       
  • The pathogenicity of novel duck reovirus in Cherry Valley ducks
    • Abstract: Publication date: Available online 25 July 2016
      Source:Veterinary Microbiology
      Author(s): Ning Li, Tianqi Hong, Yao Wang, Youling Wang, Kexiang Yu, Yumei Cai, Sidang Liu, Liangmeng Wei, Tongjie Chai
      The novel duck reovirus (NDRV) is an emerging, contagious infection. To better realize the pathogenic mechanism of NDRV in ducks, an infection experiment was conducted. The resulting data demonstrated that typical gross lesions were observed in the infected ducks. NDRV was able to replicate in various tissues, leading to these pathological lesions, especially on the liver and spleen. Real-time quantitative PCR showed that the expression of most innate immune-related genes was up-regulated and the antiviral innate immune response could be established in both the liver and spleen. This study indicates that NDRV is a pantropic virus. To resist viral infection, several pathogen recognition receptors can cooperatively recognize NDRV and initiate innate immunity, but the responses are different between different tissues. As far as we know, this is the first systematic investigation of the pathogenicity of NDRV in Cherry Valley ducks based on the host’s innate immunity, and these data will provide new insights into the further study of the disease.


      PubDate: 2016-07-29T19:47:54Z
       
  • Evidence for an independent third Usutu virus introduction into Germany
    • Abstract: Publication date: Available online 16 June 2016
      Source:Veterinary Microbiology
      Author(s): Ute Ziegler, Christine Fast, Martin Eiden, Sabine Bock, Christoph Schulze, Dirk Hoeper, Andreas Ochs, Patricia Schlieben, Markus Keller, Dorothee E. Zielke, Renke Luehken, Daniel Cadar, Doreen Walther, Jonas Schmidt-Chanasit, Martin H. Groschup
      Usutu virus (USUV) is an arbovirus within the genus flavivirus, which was first introduced to Southern Europe approximately twenty years ago causing epizootics among wild and captive birds. In Germany USUV was initially discovered in wild birds, mainly Common blackbirds (Turdus merula), in the Upper Rhine valley in southwest of the country in 2011 and has not spread much northwards since. Phylogenetic analyses revealed that the still ongoing USUV epidemic is caused by two different USUV strains, USUV-Germany belonging to the USUV Europe 3 lineage and USUV-Bonn belonging to the USUV Africa 3 lineage. The two strains were introduced independently. In August 2015 a new USUV strain, named USUV-Berlin, was isolated in Vero cells from two carcasses of juvenile Great grey owls (Strix nebulosa) kept in the Zoological Garden Berlin, which had suffered from a hyperacute fatal systemic infection. Both owls carried high USUV genome loads. Full-length USUV genomes sequences were determined and phylogenetic analysis demonstrated a close relationship with a Spanish mosquito-derived sequence from 2006. Immunohistochemical antigen detection in organ samples of the owls showed the typical USUV infection patterns. According to the phylogenetic analysis, USUV-Berlin belongs to the Africa 2 lineage, and can thus be distinguished from the other strains circulating in Germany. Repeated findings of different USUV strains suggest more frequent introductions into Central Europe and a higher mobility of this virus than assumed to date.


      PubDate: 2016-06-18T18:21:59Z
       
  • Factors associated with herd-level PRRSV infection and age-time to
           seroconversion in farrow-to-finish herds
    • Abstract: Publication date: Available online 16 June 2016
      Source:Veterinary Microbiology
      Author(s): C. Fablet, C. Marois-Créhan, B. Grasland, G. Simon, N. Rose
      Factors associated with porcine reproductive and respiratory syndrome virus (PRRSV) infection were investigated in 109 herds. Serums from four batches of pigs (4, 10, 16 and 22 weeks, 15 pigs/batch) were tested by ELISA for PRRSV antibodies. Infection by Mycoplasma hyopneumoniae (Mhp), Actinobacillus pleuropneumoniae, H1N1 and H1N2 swine influenza A viruses (swIAV) and PCV2 were detected by specific serological or PCR tests. Data related to herd characteristics, biosecurity, management housing and climatic conditions were collected during a herd visit. Factors associated with the herd’s PRRSV seropositive status were identified by logistic regression. Large herd size, the lack of disinsectisation in the gestation facilities, on-farm semen collection, a short time-period for gilt quarantine and a low temperature setpoint for the ventilation controller in the fattening room significantly increased the odds of a herd being seropositive for PRRSV. Infection by Mhp and H1N2 swIAV were associated with a PRRSV seropositive status. A Cox proportional hazards model was used to identify the factors associated with the age-time to seroconversion in infected herds. Joint housing for the gilts and sows when lactating, a large nursery pen, a small number of pens per fattening room and lack of all-in all-out management in the fattening section significantly reduced the age-time to seroconversion. A small range of temperatures controlling ventilation rate in the nursery room was also associated with time to PRRSV seroconversion. Infection by Mhp and a high PCV2 infection pressure were associated with a shorter time to seroconversion. Biosecurity measures minimising the risk of introducing PRRSV into the herd, management practices reducing contacts between animals from different batches and within batches and favourable climatic conditions should be implemented to better control PRRSV infection.


      PubDate: 2016-06-18T18:21:59Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.80.247.158
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016